Prior to the introduction of the more powerful and efficient diesel engine in locomotives used in the railroad industry, such railroad locomotives were generally underpowered. It was usually necessary, therefore, to provide each end of a railway freight car with a draft gear assembly, in order for these underpowered locomotives to start a train consist, having several cars, in motion. These draft gear assemblies were used to provide a requisite amount of slack in the coupling arrangement between adjacent ends of several such freight cars making up the train consist. As is generally well known in the railway art, this slack enabled start-up movement of the lead car and thereafter each of the following cars in succession. In other words, during start-up of the train consist the locomotive would begin taking up the slack between it and the lead car first. Then the available slack in each following car, in turn, would be taken up. This start-up procedure enabled the generally lower powered locomotive to gain sufficient initial momentum to start the train consist in motion.
Additionally, in the railway art, it is equally well known that the buff and draft forces which are generated and then applied to the railroad cars in such a coupling arrangement, during in track operation of the train consist, were normally absorbed by these draft gear assemblies. Such draft gear assemblies were mounted in a draft gear pocket located in a yoke disposed within the center sill member of the railway freight car. The railway car coupler mechanism is connected to the yoke by means of a striker plate casting. Nevertheless, these prior art type coupling arrangements resulted in undesirable dynamic loading on both the car body members and their contents. These dynamic loadings usually result in considerable wear of the various components of the coupling mechanism disposed on the freight car and depending upon the contents being transported by such car such dynamic loadings can even result in damage to such contents. It is obvious that wear of the various coupling components will require considerable maintenance to be carried out so that the car can remain in service.
However, since the introduction of the more powerful diesel locomotive, in the modern railroad industry, it has been discovered that the slack, formally required in the older style coupling arrangements, is no longer necessary to start the train consist in motion. In other words, a diesel locomotive provides the capability of starting the movement of a train consist, containing multiple freight cars, without the need for considerable amounts of slack being provided by the draft gear assemblies in the car coupling arrangements. As a result, slackless drawbar assemblies have come into widespread use in the railroad industry as the connecting arrangement for joining together the adjacent ends of a pair of railway cars in a substantially semi-permanent manner. It has been demonstrated that these slackless drawbar assemblies enable the buff and draft forces which are generated by in-track movement to be distributed throughout the car center sill member to all of the railway cars making up such train consist with less damage to both the car components and cargo.